An egg white substitute material which, briefly, is a protein derivative exhibiting whipping or emulsifying properties can be produced by treatment of a soy protein substrate with a proteolytic enzyme. The substitute egg white material can be used in a wide variety of nutritional materials and confectionaries, such as mousse.
The thrust of the art has been to convert soy protein into an egg white substitute of ever greater palatability and with ever more nearly the properties of egg white. Thus, a protein derivative, which is an enzyme hydrolyzed soy isolate, is described in "Functionality and Protein Structure", ACS Symposium 92, 1979, pp. 125-146 (J. Adler-Nissen and H. Sejr Olsen, "The Influence of Peptide Chain Length on Taste and Functional Properties of Enzymatically Modified Soy Protein"), from which it appears that a series of hydrolysates of acid precipitated soy protein have been prepared using different enzymes and different DH-values (DH is an abbreviation for degree of hydrolysis, defined hereinafter), from which it was discovered that both the whipping and emulsifying properties of these soy protein hydrolysates had an optimum in a certain DH interval. The whipping and/or emulsifying ability of these soy protein hydrolysate is good, but open to improvement.
Also, soy protein derivates with excellent whipping properties are known, but they do not have a sufficiently high nutritional value, and may even be bitter, which characteristically limits their application in food formulations. See, for example, J. Am. Oil Chemists' Soc., March 1979, Vol. 56, pp 345-349.
Workers in the art have suggested ways to alleviate some of the often present undesired properties in soy isolate hydrolysate. Thus, Adler-Nissen U.S. Pat. No. 4,100,024 teaches that bitterness can be avoided by a controlled hydrolysis of soy isolate with a microbial alkaline proteinase. Olsen U.S. Pat. No. 4,431,629, teaches that controlled hydrolysis of the soy protein coupled with removal of low molecular weight peptides from the hydrolysate by ultrafiltration produces a superior egg white substitute material from the soy protein, a material which exhibits excellent whipping and/or emulsifying ability and good nutritional value combined with absence of bitterness.
The inventors hereof believe that the egg white substitute material made by practice of this invention constitutes an improvement over the products made according to the aforementioned Olsen U.S. Pat. No. 4,431,629.